JP2015529296A - Variable stroke mechanism for internal combustion engines - Google Patents

Abstract

A mechanism for varying the stroke length of the internal combustion engine during each cycle of operation includes a first gear that is non-rotatably mounted on the engine block, and meshes with the first gear to achieve a uniform crank arm. A gear set having a second gear formed on the side and a variable cam arm for generating a variable length of piston reciprocation throughout the entire stroke cycle of the engine. The orientation of the crank arm and cam arm relative to the axis of piston reciprocation is selected such that the crank arm and cam arm cooperate to produce positive torque on the crankshaft at the piston top dead center position. The gear set is also selectively configured and dimensioned to achieve a predetermined ratio of cam arm length to crank arm length. [Selection] Figure 5

Description

  The present invention relates generally to internal combustion engines, and more particularly to so-called “variable stroke” engines in which the mechanical coupling arrangement between the reciprocating piston and the engine crankshaft changes the range of piston motion during the entire operating cycle of the engine. In general, such a mechanism has the purpose of increasing the efficiency of the internal combustion engine by achieving an effective large mechanical crank arm during the explosion stroke and an effective short mechanical crank arm during the intake stroke.

  Conventional internal combustion engines operate according to repetitive continuous movements commonly referred to as intake stroke, compression stroke, explosion stroke, and exhaust stroke. In this sense, “stroke” describes the reciprocating motion of the drive piston as it moves back and forth in the cylindrical combustion chamber in the engine housing or “block”. The term “cycle” may be used interchangeably with the term “stroke”. Thus, an engine that operates according to the above method is generally referred to as a four-stroke or four-stroke engine, which indicates that the piston must reciprocate four times within the cylinder to complete a complete power cycle. . “Cycle” is also used to describe the complete power cycle of an engine. The usage of this term follows and is well understood by those skilled in the art.

  As shown, the engine piston moves a longer or shorter distance during the intake, compression, explosion, or exhaust stroke, or any combination thereof, changing the piston speed in some part of that movement Various designs are being advanced for this purpose. For example, the so-called top dead center or bottom dead center position of the piston is moved up or down every rotation or every two rotations. All of these states are various forms of variable stroke engines. Chadbourne U.S. Pat. No. 1,326,129 and Clarke U.S. Pat. No. 4,044,629 describe an extended expansion stroke. The actual application of the extended explosion process is a Millenia model car manufactured by Mazda, which utilizes a so-called Miller cycle engine of the type designed in 1947 by American engineer Ralph Miller. Miller's engine is sometimes used in ships and fixed power systems. The purpose of engineering is to reduce the compression ratio of the engine without interfering with the power generating explosion stroke. In a Miller cycle engine, the piston rises 1/5 of its stroke before the intake valve is closed. After combustion occurs on the stroke, the explosion gas pushes the piston all the way down, so the expansion ratio is not affected.

In the first half of the 20th century, it is common among those skilled in the art of internal combustion engines that the combustion products in the engine cylinder must be removed as completely as possible after each explosion stroke and during the exhaust stroke before the subsequent intake stroke. Accepted. Many different patents propose different ways to obtain a larger exhaust stroke. See, for example, US Pat. No. 1,326,733 to Hulse, US Pat. No. 2,394,269 to Svete, US Pat. No. 1,786,423 to Caddy, US Pat. No. 1,964,096 to Tucker, and US Pat. No. 1,278,563 to Austin. Chadbourne U.S. Pat. No. 1,326,129 and Clarke U.S. Pat. No. 4,044,629 are also related to larger exhaust and explosion strokes. However, due to exhaust gas regulations implemented in the second half of the 20th century, a part of the exhaust gas is used as a means to reduce the emission of NO _x (nitrogen oxide) caused by oxidation of nitrogen in the combustion chamber to the atmosphere. New engine designs that are recirculated or maintained in This is accomplished by depressurizing the intake manifold and drawing exhaust gas through the EGR (Exhaust Gas Recirculation) valve into the intake manifold.

  Others used a variable stroke design to change the engine compression ratio. In Europe and Japan in particular, much work has been done to achieve the so-called variable compression ratio by changing the position of the piston relative to the cylinder head.

  The compression ratio is the ratio between the volume of the cylinder and the volume of the combustion chamber, in other words, the air / fuel mixture that goes into the cylinder during the intake stroke is compressed by the same value as the value of the compression ratio. In general, the higher the compression ratio, the higher the engine efficiency. There are several limitations such as pre-ignition of the mixture, knocking, engine temperature, and engine structure. Since the compression ratio is one of the main factors affecting engine efficiency, it is desirable to optimize it for various operating conditions (speed rate, load, acceleration, etc.). Schechter U.S. Pat. No. 5,165,368 describes a representative example of such an institution.

  Variable piston stroke application is also utilized to optimize the pressure acting on the piston. For this purpose, the piston speed is reduced relative to the speed of a conventional piston near top dead center, maximizing the combustion process and the resulting force acting on the piston. Schaal et al., US Pat. No. 5,158,047, Williams, US Pat. No. 5,060,603, and McWater, US Pat. Nos. 3,686,972, 3,861,239, and 4,152,955 are representative examples of this concept.

  More recently, U.S. Pat. No. 5,927,236 discloses that a gear set arrangement connects an engine piston connecting rod and crankshaft via an offset support surface to achieve piston stroke length variation throughout the engine output cycle. An internal combustion engine design utilized for this purpose is disclosed. In particular, this design increases the piston stroke by increasing the effective crank arm length during the explosive part of the power cycle, increasing the torque output, and reducing the stroke and piston speed during the intake or intake and exhaust parts of the cycle. Everything is going to increase efficiency, and thereby all increase the thermal efficiency of the engine.

  Basically, the object of the present invention is to further evolve the invention of the aforementioned US Pat. No. 5,927,236.

  In particular, the object of the present invention is to take advantage of improvements in the variable stroke mechanism of the design of US Pat. No. 5,927,236 to further enhance torque output, horsepower output, fuel efficiency, volumetric efficiency, and emission reduction in internal combustion engines. Is to achieve.

  For those purposes, the present invention provides an improved internal combustion engine that is operable according to a four stroke cycle, wherein the piston moves in the first direction, the intake stroke moving in the first direction. Reciprocating motion in the combustion chamber through the compression stroke, the explosion stroke moving in the first direction, and the exhaust stroke moving in the second direction. The piston position at the end of the compression stroke and the start of the explosion stroke is defined as top dead center. Basically, the engine of the present invention comprises an engine block defining at least one combustion chamber, a crankshaft rotatably mounted on the engine block, and a piston disposed in the combustion chamber for reciprocation along the chamber axis. And a connecting rod pivotally attached to the piston.

  According to the present invention, a mechanism for creating a variable stroke length in an internal combustion engine is a mechanical gear for rotatably connecting a connecting rod to a crankshaft to convert the reciprocating motion of a piston into the rotational motion of the crankshaft. Use the assembly. Basically, the machine assembly includes a gear set including at least a first gear member that is non-rotatably attached to the engine block and a second gear member that meshes and engages with the first gear member. The second gear member has a first support surface to which the connecting rod is attached, and a second support surface attached to the crankshaft for rotation of the crankshaft and the second gear member. The second support surface is offset from the crankshaft axis for movement in a circular path around the crankshaft axis to press the uniform mechanical crank arm against the crankshaft throughout the engine's four stroke cycle. The first and second support surfaces are spaced apart from each other by an offset distance to alternately move the first support surface around the crankshaft in an inner and outer elliptical path to press the variable cam arm against the crankshaft. Accordingly, the sum of the crank arm and cam arm changes the length of the piston reciprocation throughout the engine's four stroke cycle.

  According to one aspect of the present invention, the inner and outer elliptical paths of the first support surface are combusted so that the crank arm and cam arm cooperate to produce positive torque on the crankshaft at the top dead center position of the piston. Intersect in the room or at a point adjacent to it. For example, according to one embodiment of the present invention, the inner and outer elliptical paths of the first support surface intersect at a point that coincides with the combustion chamber axis. Alternatively, the inner and outer elliptical paths of the first support surface may be used at the end of the exhaust stroke and at the intake stroke to allow the combustion chamber to maintain a predetermined exhaust volume when starting the subsequent intake stroke. In order to ensure that the position of the piston at the start of the cylinder is at a predetermined distance below the top dead center position, a predetermined or less than or equal to about 25 ° in front of the combustion chamber axis in the direction of rotation of the crankshaft. You may intersect at points separated by different angles.

  According to another aspect of the invention, the first and second support surfaces of the second gear member are selectively configured to achieve a predetermined ratio of cam arm length to crank arm length. And the dimensions are determined. Preferably, the cam arm length is at least about 20% of the crank arm length and can be no more than about 100% of the crank arm length.

  In accordance with a related aspect of the invention, the ratio of cam arm length to crank arm length is selected to achieve a predetermined volume in the combustion chamber at the end of the intake stroke.

  The first gear member may preferably be a pinion gear, and the second gear member preferably meshes with the pinion gear around the radially inner surface of the annulus so as to move around in a planetary gear manner. A crown gear portion having formed gear teeth. In this method, the connecting rod may rotate on the first support surface and the second support surface may rotate on the crankshaft.

  The present invention is applicable to virtually any internal combustion engine, preferably a multi-cylinder engine having a plurality of combustion chambers and corresponding gear sets with a number less than or equal to the number of combustion chambers. Can do.

FIG. 1 is a perspective view of an improved internal combustion engine with a mechanical assembly for producing a variable length of piston stroke according to a preferred embodiment of the present invention.

FIG. 2 is a perspective view of the variable stroke mechanism according to the embodiment of FIG.

3 is a schematic sectional view of the internal combustion engine of FIG. 1 and the variable stroke mechanism of FIG.

FIG. 4 is a second cutaway view of the variable stroke mechanism shown in FIG.

FIG. 5 is a schematic view of an explosion stroke of an internal combustion engine having a variable stroke mechanism according to a preferred embodiment of the present invention.

FIG. 6 is a schematic view of an exhaust stroke of the internal combustion engine according to the embodiment of FIG.

FIG. 7 is a schematic view of the intake stroke of the internal combustion engine according to the embodiment of FIG.

FIG. 8 is a schematic view of a compression stroke of the internal combustion engine according to the embodiment of FIG.

FIG. 9 is a schematic diagram comparing the embodiment of the present invention shown in FIGS. 5-8 to the invention of US Pat. No. 5,927,236.

FIG. 10 is a schematic view similar to FIGS. 5-8 depicting an alternative embodiment of a variable stroke mechanism for an internal combustion engine according to the present invention.

FIG. 11 is a graph depicting comparative torque curves of an internal combustion engine equipped with a variable stroke mechanism according to the present invention and a conventional four-stroke internal combustion engine.

FIG. 12 schematically illustrates the different paths followed by the cam arm and crank arm in different embodiments of the variable stroke mechanism of the present invention that utilize different selective variations in the ratio of cam arm length to crank arm length. Draw on.

FIG. 13 is a chart that collects comparative data for different selective variations in the ratio of cam arm length to crank arm length in an embodiment of the present invention.

  Referring back to the accompanying drawings, initially FIGS. 1-4, an improved internal combustion engine according to a preferred embodiment of the present invention is indicated generally at 10 and includes a conventional engine block 12. It should be noted that the engine block 12 is only partly and schematically shown as a support for a machine assembly according to the present invention. Further, for illustrative purposes, the engine is shown only as a two cylinder engine. Nevertheless, it will be readily appreciated by those skilled in the art that the mechanism of the present invention may be virtually adapted to various configurations for any multi-cylinder engine.

  A typical ordinary crankshaft 16 is provided with a crankshaft support surface 17 at the joint between the crankshaft 16 and the engine block 12. A support cap 19 formed as a conforming arch formed with two bolts and a curved support surface 21 formed as an underside thereof are attached to the engine block 12, and the opening of the engine block and the support cap 19 are mounted. , Receive normal bolts and attach a support cap 19 to the engine block 12 to hold the crankshaft 16 in place.

  The engine block is formed with two cylindrical holes 14 (FIGS. 3 and 4) in which two normal pistons 22 are arranged for reciprocating movement. Two identical conventional connecting rods 24 are pivotally attached to the piston 22 and then attached to the crankshaft 16 by the mechanical assembly of the present invention in the manner described in more detail below. Conventional end caps 26 are attached to the connecting rods 24 and hold them in a rotatable manner in combination with the crankshaft 16. As will be seen in more detail below, the connecting rod 24 is not directly attached to the crankshaft 16, but is attached to the support surface of the mechanism of the present invention.

  The mechanical assembly of the present invention includes a gear set 30 attached to the crankshaft 16 in combination with each piston and connecting rod assembly such that the gear set 30 forms the main drive portion of the present invention. Each gear set 30 includes a first gear member 32, preferably in the form of a pinion gear, in operative meshing engagement with a second gear member 36, preferably in the form of a crown gear. An eccentric counterweight 20 is attached to the crankshaft for counterbalancing, as is common in two cylinder engines. The gear set 30 is configured as a mirror image of each other that essentially divides the engine 10 into two mirror image halves with the gear set 30 in the center.

  Referring to FIG. 2, the first gear member 32 is shown in the preferred form of a pinion gear, which has a cylindrical body with teeth 34 around it. The second gear member 36 is shown in the preferred form of a crown gear, which has a cup-like generally cylindrical gear body 37 having a continuous tooth row 38 formed around its radially inner annular surface. The two first gear members 32 are separated and attached to a cylindrical support member 35 that is secured to the engine block 32 by a clamping member 33 as seen in FIG. Each first gear member 32 is thereby secured in place within the engine block against rotation. The teeth of the second gear member 36 are engaged and engaged with the teeth of the first gear member 32 for rotation of the second gear member 36 around the first gear member 32 in a planetary manner.

  Returning to FIGS. 3 and 4, a more schematic illustration of the mechanism according to the invention is given. Here again, the engine block is shown only partially and schematically, as indicated generally at 12, to depict a single cylinder 14 in which the piston 22 moves.

  The second gear member 36 includes a support member 48 in the form of an annular hub that is linearly displaced from the internal gear teeth 38 and protrudes axially outward from the exterior side of the opposite cup-shaped gear body 37. The support member 48 includes a first outer annular support surface 40 formed around the outer surface to which the connecting rod 24 is rotatably mounted, and a second support surface 42 formed around the radially inner surface of the support member 48. Have The internal support surface 42 has a cylindrical shape with a central axis common to the cup-shaped cylindrical gear body 37. The outer support surface 40 is also cylindrical, but is eccentric with respect to the axes of the inner support surface 42 and the gear body 37 so that the body of the support member 48 is the maximum offset distance described in more detail below. It has an offset position 44 enlarged in the radial direction between the support surfaces 40, 42 defining 46. The support member 48 that defines the support surfaces 40 and 42 may be formed integrally with the gear member 36, but this is not a clear condition. The only requirement is that the support member 48 must rotate integrally with the gear member 36, and integral formation is the simplest way to achieve this result.

  As can be understood with reference to FIGS. 3 and 4, three axes of rotation are thereby defined by the machine assembly of the present invention. The crankshaft 16 rotates about the crankshaft axis 70, which is the geometric axis of the first gear member 32 (ie, the gear member 32 is attached to its engine block as seen in FIGS. 3 and 4). The axis that will rotate if it allows free rotation). The arrangement of the first gear member 32 can be adjusted to allow a slight degree of rotational adjustment about the crankshaft axis 70. The second gear member 36 (including its integral gear member 48) rotates about an axis that is parallel except that it is offset from the crankshaft axis 70 by a predetermined offset distance 50. This crankshaft offset 50 is present in any crank-driven internal combustion engine and produces a non-fluctuating mechanical crank arm that acts on the crankshaft 16 through which piston pumping reciprocating motion is converted into crankshaft 16 rotation. Due to the eccentric orientation of the support surface 40, the connecting rod 24 rotates about a separate axis 74, which also extends parallel to the crankshaft axis 70 and the offset axis 72. The distance between the offset axis 72 and the connecting rod axis 74 defines the maximum offset distance 46 imposed on the variable cam arm acting on the crankshaft 16. In this manner, the maximum offset distance 46 is combined with the crankshaft 50 to define the total effective crank length, which varies according to cam arms that vary throughout the engine operating cycle, as will be described in more detail below. .

  Those skilled in the art will recognize that the engine is described as having a valve system, a cooling system, an ignition system, and associated structural elements to provide a fully operable internal combustion engine. An engine necessarily includes these systems and elements, but such systems and elements need not be different from the normal elements and systems in a standard internal combustion engine. Here, such elements are beyond the scope necessary for the description and understanding of the invention and are therefore omitted so that the invention can be more clearly described. Any suitable valve system, cooling system, ignition system, and related structural elements will work satisfactorily with the present invention. It should be noted that the present invention is applicable to virtually any standard crank drive internal combustion engine.

  Like a normal internal combustion engine, the explosion of the air fuel mixture in the combustion chamber portion of the cylinder 14 above the piston 22 drives the piston downward and causes the crankshaft 16 to rotate. Multi-cylinder engines provide multiple piston / cylinder arrangements arranged for continuous explosion of a predetermined sequence of air fuel mixture for smooth engine operation. In general, the greater the number of cylinders, the smoother the engine will operate. Although the present invention is shown as a two-cylinder engine, the present invention is fully applicable to engines having virtually any number of cylinders. The present invention is equally applicable to spark ignition engines, diesel and other compression ignition engines, and radial engines.

  The improvement of the present invention operates to vary the effective stroke length (ie, the range of piston travel throughout the entire four strokes of a complete engine operating power cycle). The engine according to the invention operates according to a modified Atkinson cycle, in which the complete cycle of engine operation consists of four separate strokes (i.e. intake or intake stroke; compression stroke; explosion or power stroke; and exhaust or exhaust stroke). ). During the intake stroke in a given cylinder, the associated intake valve for the cylinder is opened while the piston is drawn down by the rotation of the crankshaft, thereby accepting the air fuel mixture into the combustion chamber. During the compression stroke, the intake valve is closed while the piston reciprocates upward, compresses the fuel-air mixture in the combustion chamber to a predetermined degree, and the compressed fuel-air mixture explodes a predetermined number of times. For example, when the spark plug associated with the cylinder is burned, and thus the gas produced by the combustion expands, the explosion stroke is initiated by driving the piston down again through the cylinder. At the completion of the explosion stroke, the exhaust valve for the cylinder is opened when the piston begins to reciprocate again upward in the cylinder to perform the exhaust or exhaust stroke, during which time the piston passes through the exhaust valve through the combustion chamber. Then, the waste combustion gas is driven out and the four stroke engine is prepared to repeat four strokes or four cycles. The so-called stroke length is defined as the distance that the piston travels in the combustion chamber during each of the four strokes of the operating cycle. In conventional internal combustion engines, the stroke length is fixed and does not change throughout the four operating strokes of the engine operating power cycle.

  In contrast, the present invention operates to provide a variable stroke length. Since the teeth of the second gear member 36 are formed on the inner surface thereof, the second gear member 36 rotates in a planetary manner around the first gear member 32 in the same direction as the crankshaft 16 rotates. The meshing between the first and second gear members 32, 36 is selected to give a gear ratio of 1: 2, whereby the support member 48 and thereby its offset portion 44 and maximum offset spacing 46 are The shaft 16 is rotated by one and a half rotations for every single rotation of the shaft 16. The effects of this mechanical action are depicted in FIGS. 5-8, each of which represents a single stroke of the engine's operating power cycle.

  Returning to FIGS. 5-8, the stroke of the piston 22 and associated gear machine assembly of the present invention, which couples the piston 22 to the crankshaft 16 via the connecting rod 24, includes the explosion or power stroke, the exhaust stroke, the intake stroke, And depicted schematically continuously throughout the compression stroke. In each of FIGS. 5-8, each stroke is drawn with an initial start position, an intermediate position, and a final position, sequentially indicated by characters, and the final position of one stroke is also under the same character designation. Constitutes the first position of the next following stroke. Thus, the explosion or power stroke of the assembly is schematically depicted in FIG. 5 and is indicated by the initial position of the piston 22 indicated by A (generally referred to as the “top dead center” position), B. Intermediate drive position and a final position indicated by C. FIG. 6 depicts the initial, intermediate and final positions of the assembly in the exhaust stroke after the explosion / power stroke at C, D and E. FIG. 7 depicts the initial, intermediate and final positions of the assembly in the intake stroke after the exhaust stroke at E, F and G. FIG. 8 depicts the initial, intermediate and final positions of the piston 22 in the compression stroke after the intake stroke at G, H and A.

  5 to 8, the longitudinal center line axis of the cylinder 14 of the engine block 12 in which the piston 22 reciprocates is indicated by 102, and the rotation axis of the crankshaft 16 is indicated by 70. A junction point representing the connection between the connecting rod 24 and the support member 48 coincident with the axis 74 is indicated schematically at 52 and is spaced apart representing the connection between the crankshaft 16 and the support member 48 coincident with the axis 72. The junction point is indicated at 54, and the spacing between the respective junction points 52, 54 represents the maximum offset interval 46. The mechanical crank arm acting on the crankshaft 16 by the crankshaft offset is represented by 50 as extending between the joint 54 between the support member 48 and the crankshaft 16 and the crankshaft 70, and depending on the maximum offset distance. The resulting variable cam arm is represented at 46 as extending between a junction 52 between the connecting rod 24 and the support member 48 and a junction 54 between the support member 48 and the crankshaft 16. During rotation of the crankshaft 16 about its axis 70, the support member / crankshaft junction 54 follows a concentric circular path 56 about the crankshaft axis 70 as the assembly rotates. Due to the spacing of the axes 72, 74 by the offset 46, the connecting rod / offset junction 52 follows two separate elliptical paths that occur alternately between the outer elliptical path 58 and the inner elliptical path 60.

  As will be appreciated, however, for the presence of the mechanical gear assembly of the present invention, the connecting rod 24 would otherwise be joined to the crankshaft 16 at 54 like a normal engine. Instead, as depicted in FIG. 5, the cam arm generated by the maximum offset 46 and the cam arm generated by the crankshaft offset 50 in the present mechanical gear set assembly together are pistons with an explosion / power stroke of B. Effectively increases the stroke length of the piston 22 after the explosion as it travels through the middle position of 22 to the final position of C. In particular, during the explosion stroke, the joint 52 between the support member 48 and the connecting rod 24 follows its outer eccentric path 58, whereby the assembly proceeds through position B in FIG. 16 rotates 1/2, during which the cam arm produced by the maximum offset 46 acts to add to the crankshaft offset 50 to increase the effective stroke length, so that the explosion stroke reduces the effective total crank length. Completed at that maximum. This increase in the effective stroke length acts to increase the work performed by the engine 10 in the explosion stroke. At this point, the explosion process begins.

  During the subsequent explosion stroke, as indicated by piston positions C, D, and E in FIG. 6, the crankshaft / offset joints 54 are offset / connecting rods as the joints 52, 54 travel along their respective paths. Past the joint 52, so that at the end of the explosion stroke, the joints 52, 54 are essentially reversed to their relative positions from the beginning of the explosion stroke of FIG. 5A, thereby the full length of the piston stroke during the exhaust stroke. Is substantially the same as the piston stroke length of the explosion stroke. As a result, the piston exhausts combustion gases and by-products completely from the combustion chamber.

  FIG. 7 shows the intake stroke for aspirating the fuel / air mixture by the piston 22, starting at the final position E of the exhaust stroke of FIG. During this part of the operating cycle, the offset / connector joint 52 follows its inner path 60 and the effective stroke length is progressively reduced, at which time the assembly advances to position F and passes through position F to complete the suction stroke. Proceed to position G and the effective stroke length is reduced to its minimum length by an amount equal to the crankshaft offset 50 which is less than the maximum offset 46. From the initial position E to the final position G in FIG. As a result of the reduction in the effective stroke length during the intake stroke, the amount of work the engine must perform when retracting the piston and receiving the fuel / air mixture into the combustion chamber 14 is correspondingly reduced, reducing the use of fuel. Achieve the same reduction. The speed at which the piston 22 moves downward during the intake stroke is correspondingly slower than during the preceding explosion and exhaust strokes.

  FIG. 8 depicts the subsequent compression stroke starting at position G at the end of the suction stroke. As the assembly travels through the intermediate position H and returns to the start position A to begin another explosion stroke, the offset / connecting rod joint 52 ends its movement through its inner path 60 and once again at its outer side. Move to path 58.

  The present invention provides several advances over the invention of US Pat. No. 5,927,236. According to one aspect of the present invention, the gear set 30 is such that the connection between the support member 48 of the second gear member 36 and the connecting rod 24 is followed by a junction 52 (ie, an axis 74 for the connecting rod 24). Oriented outer and inner elliptical paths 58, 60 and arranged to intersect at or close to the point of the combustion chamber axis 102 so that the mechanical crank arm and cam arm cooperate with the piston The crankshaft is caused to generate a positive torque at the top dead center position. In particular, FIGS. 5-8 depict one embodiment of the present invention in which the intersection of the elliptical outer and inner paths 58, 60 coincides with the cylinder / combustion chamber axis 102. In contrast, as depicted in FIG. 9, in the preferred embodiment shown and described in US Pat. No. 5,927,236, the intersection of the outer and inner paths 58, 60 is relative to the direction of rotation of the crankshaft. When viewed, it is oriented 90 ° before the cylinder axis 102.

  Advantageously, the altered orientation of the machine arrangement in the present invention, when viewed in comparison in FIG. 9, is expanded to act on the piston at its top dead center position relative to the preferred embodiment of US Pat. No. 5,927,236. A mechanical crank arm is created and the mechanical crank arm and associated crankshaft torque are improved in the same way over the full range of the engine's four cycles. The expansion of the crank arm is particularly noticeable when compared to a conventional engine without any variable stroke arrangement as shown in the graph of FIG. In FIG. 11, curve 104 plots a mechanical crank arm (millimeter measurement) produced by a 1000 cc displacement four cylinder engine embodying the present invention against the crank angle of the engine over its four cycles or strokes, Curve 106 plots as a comparison a mechanical crank arm generated in a conventional 1000 cc displacement four-cylinder engine in which the piston connecting rod is connected directly to the crankshaft without any machine or other arrangement that changes the piston stroke. .

  As shown by curve 106, conventional engines experience a significant amount of negative torque on the crankshaft during the compression stroke as they approach the explosion / power stroke, typically burning 35 ° before top dead center position. Require sparks to be ignited as much as possible. In such engines, the piston must perform negative work to overcome negative torque, which continues to dominate until a torque value of zero is achieved at top dead center (TDC) No significant amount of positive torque is generated until about 16 ° after the point position (ATDC). This is the main reason that conventional engines are generally unable to idle at speeds below about 800 RPM. In contrast, the present invention is oriented to the intersection of outer and inner elliptical paths 58, 60 followed by junction 52 (ie, axis 74 for connecting rod 24) at or in close proximity to combustion chamber axis 102. In this arrangement, the increased crank arm generates a positive torque that increases from 35 ° before the top dead center position to the top dead center position, and 16 ° after the top dead center position. Is more than twice that of conventional engines.

  As depicted in FIG. 10, an alternative embodiment of the present invention is possible in which the intersection of the outer and inner elliptical paths 58, 60 is within about 25 ° of the combustion chamber axis. In particular, FIG. 10 shows that the mechanical arrangement of the present invention can be seen on the outer and inner points at a pre-determined angle that is equal to or less than about 25 ° of the combustion chamber axis when viewed in the direction of crankshaft rotation. It is configured to point the intersection of elliptical paths 58,60. Position A ′ in FIG. 10 depicts the piston and other related mechanical components of the present invention at the beginning of the explosion stroke, ie, top dead center, and this arrangement is such a position as compared to US Pat. No. 5,927,236. It can be seen that still produces a significantly enlarged mechanical crank arm acting on the piston. Furthermore, an additional advantage achieved by this arrangement is that the piston position at the end of the exhaust stroke and at the start of the intake stroke is predetermined below the top dead center position as represented by position E ′ in FIG. There is an interval to be made. This selective orientation of the machine arrangement allows the combustion chamber to hold a predetermined amount of exhaust gas when initiating the intake stroke, which in turn contributes to reducing harmful emissions from the engine. To do.

  Also, the selective variation of the ratio of the length of the cam arm 46 to the length of the crank arm 50 can selectively vary the relevant functional variables of the combustion chamber volume and compression to expansion ratio at the end of the intake stroke. It's been found. For example, it is contemplated that the cam arm length may vary from at least about 20% of the crank arm length to about 100% of the crank arm length. Such variation may be achieved by varying the dimensions and eccentricity of the outer and inner support surfaces 40, 42 of the support member 48 to achieve different selection crank arms 50 and different selection cam arms 46. FIG. 12 shows the outer and inner elliptical paths 58, 60 followed by the junction 52 (ie, the axis 74 for the connecting rod 24) when the cam arm to crank arm ratio is selectively varied in 20% increments. Schematically depicts the relative changes and differences produced by the configuration (size and shape). The chart of FIG. 13 edits the comparison data for associated variables that are affected by such changes. In particular, the data compiled in this chart is 15: 1 for a 1000 cc displacement engine, ie a 10: 1 fixed compression ratio for an engine using spark ignition combustion or an engine using compression to ignite combustion. A fixed compression ratio of 1000 cc and a fixed intake cycle of 1000 cc are assumed. Overall, the chart shows that increasing the cam arm to crank arm ratio achieves significant advantages over a conventional engine with 1000cc displacement comparable in fuel consumption (miles per gallon) and torque. . For example, with a 70% cam arm to crank arm ratio in such a 1000 cc engine, the engine achieves an expansion capacity of 1739 cc and an expansion ratio of 16.7: 1 is achieved with a 10: 1 compression ratio. In practice, this configuration of a 1000 cc engine according to the present invention will produce 1739 cc engine torque and horsepower output, but will only consume the same amount of fuel as a conventional 1000 cc engine.

  Therefore, it will be readily appreciated by those skilled in the art that the present invention is open to wide utility and application. Many embodiments and adaptations of the invention other than those described, as well as many variations, modifications, and equivalent arrangements will be apparent from the invention and its foregoing description without departing from the substance or scope of the invention. Or would be reasonably suggested. Accordingly, although the present invention is described in detail herein with reference to preferred embodiments thereof, this disclosure is merely illustrative and exemplary of the invention and is made merely for the purpose of providing a thorough and feasible disclosure of the invention. It should be understood that The above disclosure is not intended or construed as limiting the invention or otherwise excluding such other embodiments, adaptations, variations, modifications, and equivalent arrangements. It is limited only by the claims appended hereto and their equivalents.

Claims (14)

An engine block defining at least one combustion chamber; a crankshaft attached to the engine block for rotation about a crankshaft axis; and a piston disposed in the combustion chamber for reciprocation along the chamber axis A connecting rod pivotally attached to the piston, and a mechanical assembly for rotatably connecting the connecting rod to the crankshaft to convert the reciprocating motion of the piston into rotational motion of the crankshaft, at least the engine block An internal combustion engine comprising: a first gear member non-rotatably attached to the first gear member; and a mechanical assembly including a gear set including a second gear member meshingly engaged with the first gear member,
An internal combustion engine is operable in accordance with a four-stroke cycle, and a piston moves in a first direction, a compression stroke moves in a second direction, an explosion stroke moves in a first direction, and an exhaust moves in a second direction. Reciprocating in the combustion chamber throughout the stroke, the piston position at the end of the compression stroke and the start of the explosion stroke is defined as the top dead center,
The second gear member includes a support portion having a first support surface to which the connecting rod is attached, and a second support surface attached to the crankshaft for rotation of the crankshaft and the second gear member;
A second support surface is offset from the crankshaft axis to move in a circular path around the crankshaft axis to press the uniform mechanical crankarm against the crankshaft throughout the engine's four-stroke cycle;
The first and second support surfaces are separated from each other by an offset distance, and the first support surface is alternately moved around the crankshaft in an inner and outer elliptical path to press the variable cam arm against the crankshaft;
The sum of the crank arm and cam arm changes the length of piston reciprocation throughout the engine's four-stroke cycle,
The inner and outer elliptical paths of the first support surface are at points at or adjacent to the combustion chamber axis to cooperate the crank arm and cam arm to produce positive torque on the crankshaft at the top dead center position of the piston. An internal combustion engine that intersects.   The internal combustion engine of claim 1, wherein the inner and outer elliptical paths of the first support surface intersect at a point that coincides with the combustion chamber axis.   At the end of the exhaust stroke and at the start of the intake stroke to allow the inner and outer elliptical paths of the first support surface to retain a predetermined exhaust volume when the combustion chamber starts the intake stroke At a predetermined angle less than or equal to about 25 ° in front of the combustion chamber axis in the direction of rotation of the crankshaft so that the piston position is at a predetermined spacing below the top dead center position. The internal combustion engine of claim 1, which intersects at spaced points.   The first and second support surfaces of the second gear member are selectively configured and dimensioned to achieve a predetermined ratio of cam arm length to crank arm length. The internal combustion engine described in 1.   The internal combustion engine of claim 4, wherein the cam arm length is at least about 20% of the crank arm length.   The internal combustion engine of claim 5, wherein the cam arm length is about 100% or less of the crank arm length.   The internal combustion engine of claim 6, wherein the ratio of cam arm length to crank arm length is selected to achieve a predetermined volume in the combustion chamber at the end of the intake stroke.   The internal combustion engine of claim 1, wherein the second gear member includes a crown gear portion having gear teeth formed about a radially inner surface of the annular body.   The second gear member includes a support portion projecting outward from the crown gear portion, the first support surface being a support portion for rotation of the connecting rod on the first support surface and rotation of the second support surface on the crankshaft. The internal combustion engine of claim 8, wherein the second support surface is formed on an inner surface of the support portion.   2. The internal combustion engine according to claim 1, wherein the internal combustion engine is a multi-cylinder engine having a plurality of combustion chambers and a plurality of gear sets corresponding to a number smaller than or equal to the number of combustion chambers. An engine block defining at least one combustion chamber; a crankshaft attached to the engine block for rotation about a crankshaft axis; and a piston disposed in the combustion chamber for reciprocation along the chamber axis A connecting rod pivotally attached to the piston, and a mechanical assembly for rotatably connecting the connecting rod to the crankshaft to convert the reciprocating motion of the piston into rotational motion of the crankshaft, at least the engine block An internal combustion engine comprising: a first gear member non-rotatably attached to the first gear member; and a mechanical assembly including a gear set including a second gear member meshingly engaged with the first gear member,
An internal combustion engine is operable in accordance with a four-stroke cycle, and a piston moves in a first direction, a compression stroke moves in a second direction, an explosion stroke moves in a first direction, and an exhaust moves in a second direction. Reciprocating in the combustion chamber throughout the stroke, the piston position at the end of the compression stroke and the start of the explosion stroke is defined as the top dead center,
The second gear member has a first support surface to which the connecting rod is attached, and a second support surface attached to the crankshaft for rotation of the crankshaft and the second gear member;
A second support surface is offset from the crankshaft to move in a circular path around the crankshaft axis to press the uniform mechanical crankarm against the crankshaft throughout the engine's four-stroke cycle;
The first and second support surfaces are separated from each other by an offset distance, and the first support surface is alternately moved around the crankshaft in an inner and outer elliptical path to press the variable cam arm against the crankshaft;
The sum of the crank arm and cam arm changes the length of piston reciprocation throughout the engine's four-stroke cycle,
An internal combustion engine wherein the first and second support surfaces of the second gear member are selectively configured and dimensioned to achieve a predetermined ratio of the cam arm length to the crank arm length.   The internal combustion engine of claim 11, wherein the cam arm length is at least about 20% of the crank arm length.   The internal combustion engine of claim 12, wherein the cam arm length is about 100% or less of the crank arm length.   14. The internal combustion engine of claim 13, wherein the ratio of cam arm length to crank arm length is selected to achieve a predetermined volume in the combustion chamber at the end of the intake stroke.

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